Automatic grinding system



Oct. 30, 1956 w. smnszus 2,768,482

AUTOMATIC GRINDING SYSTEM Filed Nov. 3, 1952 Fig.2

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United States Patent AUTOMATIC GRINDING SYSTEM William Bindszus,Rutherford, N. J.

Application November 3, 1952, Serial No. 318,431

4 Claims. (Cl. 55-165 This invention relates to improvements in meansfor automatic control of the grinding of fine cutting edges andspecifically it refers to an automatic grinding system for cutting edges.on razor blades such as described in my Patent No. 2,692,457, datedOctober 26, 1954.

The present invention represents an improvement over the automaticcontrol device illustrated in Figures 5 and 11 in the above patent, aswill be h'ere-in after explained. It was found after the first machinewas built that the original design was giving dilliculti-es in operationdue to the fact that little particles of dust or dirt would throw thesetting ofi and would cause damage. In the present improvement thesedifficulties have been eliminated as here-in-after described.

The main object of my invention is to provide an automatic grindingsystem which will automatically adjust the grinding wheels, in theproduction of :a fine cutting edge on a strip of steel.

Another object of my invention is to provide an automatic grindingsystem which has a time delay whereby any temporary change such as dueto impurities or fine metal particles will not be adjusted for, therebypreventing the jamming of the machine.

Still another object of my invention is to provide a simple and reliableautomatic grinding control system which may be manufactured andmaintained at low cost.

Other objects and advantages of my invention will be apparent during thecourse of the following description.

*In the accompanying drawing forming a part of the specification and inwhich like numerals are employed to designate like parts throughout thesame,

Figure '1 represents a schematic wiring diagram of an automatic grindingcontrol system embodying my inven- I tion, a

Figure 2 represents a front elevation of the control lever taken alongline 22 in Figure 3, and

Figure 3 represents a side elevation of the control lever taken alongline 33 in Figure 2.

In the drawings wherein for the purpose of illustration "ice - 2 24. Thespring 24 acting through the shaft 19 holds the collar 23 tightlyagainst bearing 21 whereby the feeler gage 10 is held in a fixed angularrelation to the mounting bracket 28 and the work strip 13.

On the rear end 25 of shaft 19 is mounted counterweight 26 by means ofnut 27. The weight 26 is in the form of a cylindrical body mountedeccent-rical'ly, thus acting as a counterweight to the feeler gage 10.

The bearing block 22 is mounted upon a bracket 28 which is fastened tothe guide block 14. The feeler gage 10 is rotatable with shaft 19 inbearings 20 and 21 through a small angle as indicated in Figure 2. Astop pin 29, fastened in bracket 28 limits the extent of the travel ofthe feeler gage 10.

A mercury switch '30 is mounted in a clip 31 on the upper end of thefeeler gage 10 at a slight angle. The switch 30 is connected into acircuit :as illustrated in 'Figure 1 which will be here-in-afterdescribed. in further reference to my patent mentioned supra, it ispointed out that one of these feeler gages as here described, is mountedfollowing each grinding wheel. In the case where .a single edge strip isbeing ground, there may be 2 or 3 grinding heads as desired, but where adouble edge is being ground at one time, there may be 4 or 6 grindingheads.

In Figure 1 is illustrated the circuit showing the connections betweenthe mercury switches 80 and the other elements required. As shown in mypatent mentioned supra, a solenoid is utilized for the adjustment of thegrinding wheels. This is the solenoid designated with the numeral 32 inFigure 1. It has been found, however, that with my present arrangement,it is not necessary to have a two-way solenoid as illustrated in Figure5 of my patent mentioned supra. The one solenoid 33, 36 is noweliminated and there only remains the solenoid 34, 8'5 which operates inone direction. The incoming [leads 37 and '38, lead to a switch 39 whichis the on-oif switch for the entire system. The mercury switches 39 areconnected to one of the leads coming from switch 39. The circuit shownin Figure 1 covers both single edge and double edge grinding. Therefore,three mercury switches L30 in a group control the grinding wheels forthe upper edge, and three mercury switches '30 in another group controlthe grinding wheels for the lower edge. Following the mercury switches30 and 30, there are connected time delay relays 40 and 40, one for eachmercury switch. The output of the time delay relays 40 is connected tothe solenoids 32 for the upper group, and the output of the time delayrelays 40' is connected to the solenoids 32' for the lower group. Theother leads of the solenoids 32 and 32' are connected to a lead going tothe motor driven interrupter 41 with a switch 42 which is connectedacross the line and which runs with a constant speed preferably about 24R. P. M. A pilot lamp 43 indicates when the circuit is on. A switch 44provides connection to one side of the time delay relays 40 in the uppergroup while a switch 45 similarly connects to the time delay relays 40in the lower group. The switches 44 and 45 are used for double point ofthe cutting edge is ground olf slightly to avoid damaging theouttinged-ge. The feeler gage 10 has a threaded hole 15, see Figure 2, aslot 16 and a screw, 17. The feeler gage 10 is mounted on a finelythreaded portion 18 of the shaft 19, which is journaled in the ballbearings 20 and 21, see Figure 3. placed tightly against the block '22on one side and a collar 23 is fastened on the shaft 19 tightly againstsaid bearing 21. The bearing 20 rests against a spring washer 24 on oneside, and the larger diameter of the portion -18 of the shaft 19 holdsthe bearing 20 against said spring The bearing 21 is strip, single edgegrinding only.

The operation of my device is as follows:

The feeler gage 10 is adjusted by turning the shaft 19 with the finethread 18 in hole 15 until the tungstencarbide tip 11 touches the groundface of the cutting edge. The screw 17 is then tightened up therebyclamping the feeler gage 10 securely to the threaded portion 18 of theshaft 19. When the steel strip 13, which is to be ground, starts moving,any change in the face of the cutting edge will be detected by the tip11 of the feeler gage 10. When the machine is started up, the grindingwheels are at first adjusted by hand to a position where automaticoperation can start. When any one wheel does not remove a sufficientamount of material, the excess material will cause a pressure againstthe tip 11 of the feeler gage which will cause an increased frictionbetween the strip 13 moving in the direction shown by arrow in Figure 2and the feeler gage 10. This friction will swing the feeler gage 10 toone side as indicated in broken lines in Figure 2. When the feeler gage10 is moved to one side by friction between the point 11 of the feelergage 10 and the ground edge of the single edge strip 13 shown in Figure3, the mercury switch 30 which is normally almost horizontal, will betilted to one side and will make contact between its two poles. Whenthus the strip 13 comes through with an edge which is not suflicientlyground down the increased thickness of material on the edge willincrease the friction between same and the point 11 of the feeler gage10, the increased friction will then move the feeler gage along with themotion of the strip as indicated in dotted lines in Figure 2. This willenergize the relays which will change the setting of the grinding asdescribed in my patent mentioned supra and more material will be groundoff the edge of the strip 13. This again will result in less frictionbetween the point 11 and the moving strip 13. After this has beenreduced to a certain point, gravity will return feeler gage 10 to itsoriginal perpendicular position as indicated in Figure 2, at the sametime opening the switch 30. The switch 30, therefore, becomes gravityoperated or gravity sensitive. As indicated in the circuit diagram inFigure 1, the mercury switches will energize the time delay relays 40.operation these time delay relays are set to give a delay of 4 seconds.If, therefore, a speck of dust or other impurity should get onto thecutting edge and should move the feeler gage 10 over temporarily, the 4seconds delay will give it a chance to fall back in its normal positionthereby opening the switch 30 and nothing will happen. If, however, thechange detected by the feeler gage is of a duration of more than 4seconds, the time delay relays 40 will give an impulse which willenergize the solenoids 32. As shown in my patent mentioned above, thesolenoids 32 will advance the grinding wheel one notch which may be lessthan .0001 inch, all according to how the mechanism is arranged. If thedeflection of the feeler gage 10 continues, then after another 4 secondsthe solenoids 32 would get a second impulse from the time delay relays40. However, the solenoids had not been reset and would not be operableat this time. I have, therefore, arranged a motor-driven switch 41, 42which has a speed of 24 R. P. M. and which thus resets the solenoidsevery 2 seconds by furnishing an operating impulse for each revolution.When, therefore, the second impulse comes from the time delay relays 40,the solenoid will move the grinding wheels forward another notch. Thisoperation will continue until sufiicient metal has been removed by thegrinding wheels so that the feeler gage 10 will return to its originalposition and will thus open switch 30. It is obvious that any one of theswitches 30 with its connected time delay relay 40 is operatingindividually and is adjusting the grinding wheel which is preceding it.

If a double edge strip is ground such as used for or dinary safetyrazors of the Gillette type, then the same operation will occur on thelower edge where the three grinding wheels will be adjustedautomatically by means of three mercury switches 30' and the connectingtime delay relays 40 working into the solenoids 32. In this manner it ispossible to set up a machine for grinding both single and double edgeblades just by changing the guide blocks 14.

It is to be understood that the form of my invention, herewith shown anddescribed, is to be taken as a preferred example of the same and thatvarious changes in the shape, size and arrangement of parts may beresorted In normal to, without departing from the spirit of my inventionor the scope of the subjoined claims.

Having thus described my invention I claim:

1. An automatic control system of the character described comprising afeeler gage mounted adjacent to a moving strip to be ground, said feelergage having a free swinging lever, one face of the end of said leverswinging parallel to and in sliding contact with the surface beingground, the other end of said lever being mounted upon a shaftjournalled in bearings upon a fixed support; a gravity sensitive switchmounted upon the journalled end of said lever; electrical control meansoperable by said switch, and an electrical delay circuit interposedbetween said switch and said electrical control means.

2. An automatic control system of the character dcscribcd comprising afeeler gage adapted to gaging a moving strip, said feeler gage having alever mounted in parallel and right angle relation to said strip, saidlever being mounted upon a rotatable shaft near one end and having itsother end in frictional contact with said strip and free to swing alongthe path of said moving strip; a gravity sensitive switch mounted nearthe journalled end of said lever; electrical control means operable bysaid switch, and an electrical delay circuit interposed between saidswitch and said electrical control means.

3. An automatic control system of the character described comprising afeeler gage adapted to gaging the thickness of a moving strip, saidfeeler gage having a lever mounted in parallel and right angle relationto the surface to be gaged, said lever being mounted upon a rotatableshaft near one end, said shaft being adjustable axially in anti-frictionbearings and having a spring holding said shaft in a fixed axialrelation to said bearings, the other end of said lever being infrictional contact with the surface to'be gaged and free to swingparallel to and in the same direction as said moving strip; a gravitysensitive switch mounted upon said lever; electrical control meansoperable by said switch, and an adjustable electrical delay circuitinterposed between said switch and said electrical control means wherebythe action of said control means may be delayed as desired.

4. An automatic control system of the character described comprising afeeler gage adapted to gaging the changes produced by the grinding of amoving strip; said feeler gage having a lever mounted with one end on afreely rotatable shaft, said shaft being journalled in precision typeball bearings; a ball bearing housing holding said bearings; a springinterposed between one of said ball bearings and said housing; the otherend of said lever being in frictional contact with the edge to be groundon said moving strip and being free to swing through an angle along andparallel to said edge; a counterweight balancing said lever; electricalcontrol means operable by the angular displacement of said lever, and anadjustable electrical delay circuit interposed between said switch andsaid electrical control means whereby the action of said control meansmay be delayed as desired.

References Cited in the file of this patent UNITED STATES PATENTS915,671 Hanson Mar. 16, 1909 1,370,381 Tarbox Mar. 1, 1921 1,763,201 VanNorman June 10, 1930 1,891,662 Booth et al Dec. 20, 1932 2,149,409 VanNorman Mar. 17, 1939 2,264,985 Kovalsky Dec. 2, 1941 FOREIGN PATENTS366,005 Great Britain Ian. 25, 1932

